PURPOSE: To prevent deterioration of the engine performance due to misfiring, by setting a limit to the air-fuel ratio in feedback controlling the same when it is detected from variation of engine combustion that the air-fuel ratio has approached to a misfiring causing limit, so as not to render the air-fuel ratio further to the lean side.
CONSTITUTION: A lean air-fuel ratio feedback control means feedback controls the air-fuel ratio by use of an air-fuel ratio signal detected and produced by an air-fuel ratio signal generating means such that it is kept at a desired lean air-fuel ratio calculated by a lean air-fuel ratio calculating means by use of predetermined parameters relating to the operational conditions of an engine. On the other hand, a feedback control means for the limit of lean air-fuel ratio feed back controls the air-fuel ratio such that the quantity of variation in the engine combustion detected by a means for detecting the quantity of variation of engine combustion is kept at the limit of the quantity of combustion variation calculated by a means for calculating the limit of the quantity of combustion variation by use of the predetermined parameters relating to the operational conditions of the engine. By selecting either one of the above two methods, it is enabled to prevent misfiring, to purify the exhaust gas and to lower the specific fuel consumption simultaneously.
OOHAYASHI HIDEKI
KOHAMA TOKIO
KAWAI HISASHI
SHIGEMATSU TAKASHI
TOKORO SETSUO
TOYOTA MOTOR CO LTD
| JPS5827837A | 1983-02-18 | |||
| JPS5859321A | 1983-04-08 | |||
| JPS603440A | 1985-01-09 |
Next Patent: JPS6027749